The Sun’s total emissivity as measured at numerous sea level sites across the globe, and accounting for the angle of incidence of the Sun’s rays, varies by no more than 0.1% over the sunspot cycle of 11 years.
Disco- Pete, you are safe.
Green house re-radiation of course is an entirely different matter.
Disco- Pete, you are safe.
Green house re-radiation of course is an entirely different matter.
Not as far as the Sun itself is concerned, as you seemed to imply.So nothing to worry about then. 😉
The solar flux just outside the Earth's atmosphere is a constant 1373 watts per square metre.
Reflectance, scattering, and absorption of light in the atmosphere can reduce this amount by 15–80% before reaching the Earth's surface.
Am I the only one struggling to get used to the new Disco-Pete moniker?
Let's see what hyphenation would do to mine: Ga-Lu
And what about Bon-Sai?
Nope, that just don't seem right! 😀
Let's see what hyphenation would do to mine: Ga-Lu
And what about Bon-Sai?
Nope, that just don't seem right! 😀
Slowly we are inching towards seeing EM as wading thru treacle 😀
EM couples to space thru the time field.
Electromagnetism is a property of the spacetime itself, study finds
EM couples to space thru the time field.
Electromagnetism is a property of the spacetime itself, study finds
I've read that article, or similar, before and I don't understand a word of it. 😕
In fact, it sounds like a job for a geometrician like Steve!
"Tensions in spacetime" - that must be your "treacle". 🙂
In fact, it sounds like a job for a geometrician like Steve!
The upshot seems to be that the authors believe that strong EM fields change the local curvature of spacetime - a special kind of stretching and bending of spacetime.Our research shows that the Lagrangian of electrodynamics is just the Einstein-Hilbert action of general relativity; it reveals how Maxwell's equations of electromagnetism are an optimality condition for the metric of spacetime to be sufficiently flat.
"Tensions in spacetime" - that must be your "treacle". 🙂
It had to happen to fix the UCO in my acct.; very complicated, too much even for you. 🙂 Just ignore the hyphen.Am I the only one struggling to get used to the new Disco-Pete moniker?
Let's see what hyphenation would do to mine: Ga-Lu
And what about Bon-Sai?
Nope, that just don't seem right! 😀
Obviously very bored. 🙄 Perhaps you could explain the Crooked Forest, or the lightning at Lake Maracaibo?
btw, your ability to follow that is impressive 🙂
still have no idea how that misspell got in there, though. I'll think about it from time to time.
when I'm bored.
btw, your ability to follow that is impressive 🙂
still have no idea how that misspell got in there, though. I'll think about it from time to time.
when I'm bored.
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OTOH, Bonsai had some very compelling arguments in that 'out of this world' thread. But something not mentioned was how coincidentally needed our Moon is to life on this planet. It's imo more than amazing how it just happens to provide/satisfy some critical requirements to enable life here. I'm watching an episode of The UnXplained. How parallel would circumstances on another planet somewhere capable of sustaining life have to be to actually make it happen?" Without the Moon this is a warm but dead planet.
I wonder how much acceleration it could take in its final "unfolded" state (surely a lot less than when launched from Earth!) and how long it would take to move it near the Moon and back out to L2. Yet more tradeoffs on fuel, observation time at L2, and so on.Might be for repairs, it would be easier to park the JWST in moon orbit, fix it, then send it out again to L2.
Would be great to hear from someone on the program on these issues.
Am I the only one struggling to get used to the new Disco-Pete moniker?
Let's see what hyphenation would do to mine: Ga-Lu
And what about Bon-Sai?
Nope, that just don't seem right! 😀
😀
I wonder how much acceleration it could take in its final "unfolded" state (surely a lot less than when launched from Earth!) and how long it would take to move it near the Moon and back out to L2. Yet more tradeoffs on fuel, observation time at L2, and so on.
That’s why I suggested the use of a ‘tractor’ spacecraft to fetch it and take it back.
I've read that article, or similar, before and I don't understand a word of it. 😕
In fact, it sounds like a job for a geometrician like Steve!
The upshot seems to be that the authors believe that strong EM fields change the local curvature of spacetime - a special kind of stretching and bending of spacetime.
"Tensions in spacetime" - that must be your "treacle". 🙂
Hyper-theoretical giff-gaff. We should send Sabine Hossenfelder in there to sort them out! 😀
But seriously, it does seem to me that there has to be a fundamental explanation for EM. I was surprised to read in a book ('Maxwell's Equations' by Daniel Fleisch - which BTW is in the CERN Library - so its a respected University level document) delving deeply into EM equations that the underlying mechanism was a (quote) 'deeply philosophical' question that students of EM theory best leave for the time being. We've created a whole edifice of theory based upon a mechanism that does not have a rational explanation at its most fundamental level. I don't want to poison this very excellent thread with any of that other stuff, but as someone pointed out over there, the same thing applies of course to gravity - although there is some serious work underway I understand to get a universally acceptable explanation for that.
I would love to see someone recast the EM equations in terms of time and energy with a link to entropy ie you can have no change in energy without producing time, so it's entropy that becomes the 'canvass' upon which things happen and the result is time is produced, creating perturbations in what I can only describe as the time field. This may lead to an explanation of why the universe is expanding. There is no 'dark energy' but just time being produced through the action of entropy which on a cosmic scale we see as an expanding universe. But time and space are one - you can't have one without the other - a point about which Einstein went into a philosophical discussion with his friend Marcel Grossman while working on GR (See the Fraunhoffer Institute Einstein presentation by I put up a few months ago). At a local level where photons are involved, again, this is a perturbation in the time field. If you move anything with respect to something else, you shift its frame of reference. In the interaction of a photon with an electron you shift its time reference momentarily, but it snaps back to its original shell. I would like to imagine that this perturbation of the time field is the underlying mechanism for EMR. And its why gravity waves happen as well - its a perturbation of the time field. I would imagine the specific coupling mechanism may vary between say gravity waves and say photons, but the transport medium is still the time field (I don't want to sound like I'm invoking the 'ether' here).
Time my friends is not an immutable canvass upon which we conduct our lives. It is the currency with which entropy produces and trades energy with between things in the universe and its why you can transmit energy across a complete vacuum.
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Much interesting Divergence in this thread. I looked up Disco-Pete's lightning at Lake Maracaibo and the Crooked Forest. 😀
Strange trees indeed!
Crooked Forest - Wikipedia
Even weirder tree shaping here:
Tree shaping - Wikipedia
You can grow Bar stools it seems, along with much other interesting stuff like bridges and sculptures... 😎
Back to Physics. I watched an interesting YouTube lecture about whether there are higher dimensions. Could we tell? Well, you know that thing about what a 4D sphere would look like passing through our 3D section? You would see a point appear from nowhere, expand into a 3D sphere then shrink again back to a point and disappear. Bit like virtual particles!
The above link to the divergence theorem is a statement that the measurements of force on the surface of some shape in Space defines the measurements of force at every point within. Holographic, in other words. Finds applications in General relativity demanding Ricci flatness IIRC.
Also applies to Maxwell's equations of Electromagnetism.
Simply Div F = J in A Swift Introduction to Geometric Algebra - YouTube.
Bon-Sai may find it helps some of his notions about time and entropy with a dimensional recast. I must spend more time on this myself. Seems like all is just Geometric properties of Space-Time itself.
Strange trees indeed!
Crooked Forest - Wikipedia
Even weirder tree shaping here:
Tree shaping - Wikipedia
You can grow Bar stools it seems, along with much other interesting stuff like bridges and sculptures... 😎
Back to Physics. I watched an interesting YouTube lecture about whether there are higher dimensions. Could we tell? Well, you know that thing about what a 4D sphere would look like passing through our 3D section? You would see a point appear from nowhere, expand into a 3D sphere then shrink again back to a point and disappear. Bit like virtual particles!
The above link to the divergence theorem is a statement that the measurements of force on the surface of some shape in Space defines the measurements of force at every point within. Holographic, in other words. Finds applications in General relativity demanding Ricci flatness IIRC.
Also applies to Maxwell's equations of Electromagnetism.
Simply Div F = J in A Swift Introduction to Geometric Algebra - YouTube.
Bon-Sai may find it helps some of his notions about time and entropy with a dimensional recast. I must spend more time on this myself. Seems like all is just Geometric properties of Space-Time itself.
So what would you say the substance of entropy is?There is no 'dark energy' but just time being produced through the action of entropy which on a cosmic scale we see as an expanding universe. But time and space are one - you can't have one without the other - a point about which Einstein went into a philosophical discussion with his friend Marcel Grossman while working on GR (See the Fraunhoffer Institute Einstein presentation by I put up a few months ago). At a local level where photons are involved, again, this is a perturbation in the time field.
Time my friends is not an immutable canvass upon which we conduct our lives. It is the currency with which entropy produces and trades energy with between things in the universe and its why you can transmit energy across a complete vacuum.
Disco-Pete,
That is a deeply philosophical question to which, as Galu has intimated, the answer is treacle.
That is a deeply philosophical question to which, as Galu has intimated, the answer is treacle.
There is, indeed, no rational explanation of 'action at a distance' forces such as those of electromagnetism and gravity.We've created a whole edifice of theory based upon a mechanism that does not have a rational explanation at its most fundamental level.
Physicists have variously invented 'fields' and mediating 'force particles' to try to explain action at a distance, but these ideas have always been ultimately unsatisfying to me.
There's the direct interaction theory of electromagnetism, also known as Wheeler-Feynman electrodynamics, but that goes way over my head! 😱
Wheeler–Feynman absorber theory - Wikipedia
So, all grist to your mill if you can come up with how electromagnetism actually works! 😎
An attempt at humor Disco-Pete, and nothing more 🙂. The treacle thing came about because shifting the time reference of an object requires a lot of energy, even to move it only slightly - I likened it to walking thru treacle.
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